/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <android_runtime/AndroidRuntime.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <jni.h>
#include <nativehelper/JNIHelp.h>
#include <nativehelper/ScopedUtfChars.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <utils/Log.h>
#include <utils/misc.h>

namespace android {

uint64_t get_block_device_size(int fd) {
    uint64_t size = 0;
    int ret;

    ret = ioctl(fd, BLKGETSIZE64, &size);

    if (ret) return 0;

    return size;
}

int wipe_block_device(int fd) {
    uint64_t range[2];
    int ret;
    uint64_t len = get_block_device_size(fd);

    range[0] = 0;
    range[1] = len;

    if (range[1] == 0) return 0;

    ret = ioctl(fd, BLKSECDISCARD, &range);
    if (ret < 0) {
        ALOGE("Something went wrong secure discarding block: %s\n", strerror(errno));
        range[0] = 0;
        range[1] = len;
        ret = ioctl(fd, BLKDISCARD, &range);
        if (ret < 0) {
            ALOGE("Discard failed: %s\n", strerror(errno));
            return -1;
        } else {
            ALOGE("Wipe via secure discard failed, used non-secure discard instead\n");
            return 0;
        }
    }

    return ret;
}

static jlong com_android_server_pdb_PersistentDataBlockService_getBlockDeviceSize(JNIEnv *env,
                                                                                  jclass,
                                                                                  jstring jpath) {
    ScopedUtfChars path(env, jpath);
    int fd = open(path.c_str(), O_RDONLY);

    if (fd < 0) return 0;

    const uint64_t size = get_block_device_size(fd);

    close(fd);

    return size;
}

static int com_android_server_pdb_PersistentDataBlockService_wipe(JNIEnv *env, jclass,
                                                                  jstring jpath) {
    ScopedUtfChars path(env, jpath);
    int fd = open(path.c_str(), O_WRONLY);

    if (fd < 0) return 0;

    const int ret = wipe_block_device(fd);

    close(fd);

    return ret;
}

static const JNINativeMethod sMethods[] = {
        /* name, signature, funcPtr */
        {"nativeGetBlockDeviceSize", "(Ljava/lang/String;)J",
         (void *)com_android_server_pdb_PersistentDataBlockService_getBlockDeviceSize},
        {"nativeWipe", "(Ljava/lang/String;)I",
         (void *)com_android_server_pdb_PersistentDataBlockService_wipe},
};

int register_android_server_pdb_PersistentDataBlockService(JNIEnv *env) {
    return jniRegisterNativeMethods(env, "com/android/server/pdb/PersistentDataBlockService",
                                    sMethods, NELEM(sMethods));
}

} /* namespace android */